Method of detecting a defocus of an image sensor and image sensor

Abstract

A method of detecting a defocus of an image sensor and an image sensor applicable to perform the method are provided herein. The image sensor including a first subpixel and a second subpixel. The first subpixel includes m photodiode units and a first microlens structure overlaying the photodiode units, and m is an integer. The second subpixel includes m photodiode units and a second microlens structure overlaying the photodiode units. The first microlens structure is structurally different from the second microlens structure. First readout values of the photodiode units of the first subpixel are interpolated to positions of n of the photodiode units of the second subpixel to obtain interpolated values, wherein n is an integer. An imbalance value is obtained by using the interpolated values and second readout values provided by the n of the photodiode units of the second subpixel.